Variable movement headrest arrangement

ABSTRACT

The present invention involves a vehicle seat and headrest arrangement for use with a seat having a seatback in a vehicle. The vehicle seat and headrest arrangement comprises a headrest arrangement having a headrest. The headrest arrangement has one of a guide member and a follower. The seatback has the other one of a guide member and follower. The guide member has a guideway and the follower engages the guideway of the guide member such that upon impact to the vehicle forward inertia of the headrest will cause the follower to engage the guideway in such a manner as to cause the headrest to move in a manner so as to support the head of an occupant irrespective of whether occupant is in contact with the seatback.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application Ser.Nos. 60/302,016; 60/302,024; and 60/302,019, all filed on Jun. 29, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a variable movement headrestarrangement for providing support to the head of an occupant of avehicle upon vehicle impact.

2. Background Art

Improvements in safety mechanisms in the automotive industry continue tobe made year after year. Such safety mechanisms include safetyheadrests. An example of safety seat headrests can be found in Viano etal., U.S. Pat. No. 5,378,043, which is incorporated herein by reference.Such safety headrest mechanisms provide support to the head of a vehicleoccupant during crash situations.

More specifically, upon rear impact of a vehicle, the occupant of thevehicle compresses into the vehicle seatback, as the head, neck, andtorso move substantially in unison. There typically is greatercompression in the torso and buttocks regions than in the shoulderregion of the occupant. Thus, it has been a concern that the seatbackmay possibly deflect under the torso and buttocks load before the headand neck of the occupant contacts the headrest attached to the seatback.

Upon front impact of a vehicle, an occupant of the vehicle moves forwardrelative to the vehicle seatback. Upon contact with a front interiorpanel or a deployed airbag from the front panel, the occupantexperiences rebound movement in a rearward direction. Similar to a rearimpact situation as described above, the occupant in such a situationwould then provide a rearward load into the seatback and compress intothe vehicle seatback, as the head, neck, torso, and buttocks movesubstantially in unison. Thus, in a front impact it is also a concernthat the seatback may possibly deflect under the torso load prior to thehead and neck of the occupant contacting the headrest.

As a result, safety headrest mechanisms have been designed such that,upon impact having rearward movement of a seat occupant, the occupant'storso contacts an impact target of a vehicle seat with a rearward loador force. The impact target is operatively connected to a headrest orsuch that, upon the rearward load on the impact target, the headrestportion moves forward toward the head of the occupant. The forwardmovement of the headrest portion in the crash situation lessens the gapwhich may exist between the occupant's head and the headrest portion,preventing or lessening the risk of whiplash to the occupant.

However, it is desirable to have the headrest arrangement move forwardat a high initial velocity in order to decrease the gap between theoccupant's head and headrest portion more quickly, but withoutcontacting the occupant's head while moving at the high initialvelocity.

SUMMARY OF THE INVENTION

It is thus an object of the present invention to provide a costeffective mechanism to support the head of an occupant of a vehicle uponfront and rear vehicle impact.

In carrying out the above object, and other objects and features of thisinvention, a new vehicle seat and headrest arrangement for use with aseat having a seatback in a vehicle is provided. The vehicle seat andheadrest arrangement comprises a headrest arrangement having a headrest,the headrest arrangement having one of a guide member and a follower.The seatback has the other one of a guide member and follower. The guidemember has a guideway and the follower engaging the guideway of theguide member such that upon impact to the vehicle, forward inertia ofthe headrest will cause the follower to engage the guideway in such amanner to cause the headrest to move in a manner to support the head ofan occupant irrespective of whether occupant is in contact with theseatback.

In a more specific embodiment, the engagement of the follower and theguideway of the guide member together with the forward inertia of theheadrest cause the headrest to move in a first manner and a secondmanner so as to support the head of an occupant.

In another more specific embodiment, the vehicle seat and headrestarrangement further includes a damper connected between the headrestarrangement and the seatback so as to retard movement of the headrestafter it has moved in a manner so as to support the head of an occupant.

In another more specific embodiment, the guideway member is a bushinghaving a cam configuration and the follower is a cam such thatengagement of the cam and cam configuration together with the forwardinertia of the headrest cause the headrest to move in a first manner anda second manner.

In another more specific embodiment, the guideway of the guide memberhas a first guideway wall and a second guideway wall and the followerhas a first follower portion and a second follower portion which engagethe first guideway wall and second guideway wall respectively to causethe headrest to move in a first manner and a second manners so as tosupport the head of an occupant. The second guideway wall may have afirst contact portion and a second contact portion and the secondfollower portion may have a first surface portion and a second surfaceportion such that upon impact to the vehicle, the first surface portionslidingly engages the first contact portion while the first followerportion slidingly engages the first guideway wall so as to cause theheadrest to move in a first manner before the second surface portionslidingly engages the second contact portion as first follower portioncontinues to slidingly engage the first guideway wall so as to cause theheadrest to move in a second manner. The first and second contactportions and the first and second surface portions may have relativelycurved surface configurations and the first guideway wall and firstfollower portion may have relatively flat configurations substantiallyparallel to each other and inclined so as to facilitate sliding betweenthe first guideway wall and first follower portion and movement in thefirst manner.

In another more specific embodiment, the headrest arrangement includes aheadrest extension having one of a guideway member and a follower.

In another more specific embodiment, the vehicle seat and headrestarrangement further includes a movement-allowing connector connectedbetween the headrest arrangement and the seatback.

In another more specific embodiment, the vehicle seat and headrestarrangement further includes a biasing member operatively associatedwith the seatback and the headrest arrangement which tends to bias theheadrest against movement in a manner so as to support the head of anoccupant.

The vehicle seat and headrest arrangement for use with a seat having aseatback in a vehicle may also comprise a headrest arrangement includinga headrest, the headrest arrangement having at least one impact targetand at least one of a guide member and a follower. The seatback has theother at least one of a guide member and follower. The guide member hasa guideway and the follower engaging the guideway of the guide membersuch that upon impact to the vehicle one of a rearward load by theoccupant upon the impact target and the forward inertia of the headrestirrespective of whether occupant is in contact with the seatback willcause the follower to engage the guideway in such a manner to cause theheadrest to move in a manner to support the head of an occupant.

In a more,specific embodiment, the follower engages the guideway of theguide member such that upon impact to the vehicle the headrest may bemoved in a first manner and a second manner so as to support the head ofan occupant by one of a rearward load by the occupant upon the impacttarget and the forward inertia of the headrest irrespective of whetheroccupant is in contact with the seatback.

In another more specific embodiment, the vehicle seat and headrestarrangement further includes a damper connected between the headrestarrangement and the seatback so as to retard movement of the headrestafter it has moved so as to support the head of an occupant.

In another more specific embodiment, the guide member is a bushinghaving a cam configuration and the follower is a cam such thatengagement of the cam and cam configuration together with the forwardinertia of the headrest cause the headrest to move in a first manner anda second manner.

In another more specific embodiment, the guideway has a first guidewaywall and a second guideway wall and the follower has a first followerportion and a second follower portion which engages the first guidewaywall and second guideway wall respectively to cause the headrest to movein a first manner and a second manners so as to support the head of anoccupant. The second guideway wall may have a first contact portion anda second contact portion and the second follower portion may have afirst surface portion and a second surface portion such that upon impactto the vehicle, the first surface portion slidingly engages the firstcontact portion while the first follower portion slidingly engages thefirst guideway wall so as to cause the headrest to move in a firstmanner before the second surface portion slidingly engages the secondcontact portion as first follower portion continues to slidingly engagethe first guideway wall so as to cause the headrest to move in a secondmanner. The first and second contact portions and the first and secondsurface portions may have relatively curved surface configurations andthe first guideway wall and first follower portion may have relativelyflat configurations substantially parallel to each other and inclined soas to facilitate sliding between the first guideway wall and firstfollower portion and movement in the first manner.

In another more specific embodiment, the vehicle seat and headrestarrangement further includes a movement-allowing connector connectedbetween the headrest arrangement and the seatback.

In another more specific embodiment, the vehicle seat and headrestarrangement further includes a biasing member operatively associatedwith the seatback and the headrest arrangement which tends to bias theheadrest against movement in a manner so as to support the head of anoccupant.

The vehicle seat and headrest arrangement may also comprise a headrestarrangement including a headrest and a headrest extension, the headrestextension having at least one of a guide member and a follower and animpact target located below the at least one of a guide member and afollower. A seatback frame of the seatback has the other at least one ofa guide member and follower, the guide member having a guideway and thefollower slidingly engaging the guideway of the guide member such thatupon impact to the vehicle one of a rearward load by the occupant uponthe impact target and the forward inertia of the headrest irrespectiveof whether occupant is in contact with the seatback will cause thefollower to be slidably guided by the guideway such that the headrest ismoved in a first and second manner.

In another more specific embodiment, the vehicle seat and headrestarrangement further includes a movement-allowing connector connectedbetween the headrest arrangement and the seatback and a biasing memberoperatively associated with the seatback and the headrest arrangementwhich tends to bias the headrest against movement in a manner so as tosupport the head of an occupant.

The vehicle seat and headrest arrangement further includes a damperconnected between the headrest arrangement and the seatback so as toretard movement of the headrest after it has moved so as to support thehead of an occupant.

In another more specific embodiment, the guide member is fixedlyattached to the seatback frame and has a first guideway wall and asecond guideway wall and the follower is fixedly attached to theheadrest extension and has a first follower portion and a secondfollower portion which slidingly engage the first guideway wall andsecond guideway wall respectively. The second guideway wall may havefirst and second contact portions having relatively curved surfaceconfigurations, the second follower portion may have first and secondsurface portions having relatively curved surface configurations, andthe first guideway wall and first follower portion may have relativelyflat configurations substantially parallel to each other and inclinedrelative to the headrest extension such that upon impact to the vehicle,the first surface portion slidingly engages the first contact portionwhile the first follower portion slidingly engages the first guidewaywall so as to cause the headrest to move in a first manner before thesecond surface portion slidingly engages the second contact portion asthe first follower portion continues to slidingly engage the firstguideway wall so as to cause the headrest to move in a second manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vehicle seat and headrest arrangementin accordance with the present invention;

FIG. 2 is a perspective view of a variable pivot mechanism for aheadrest on a seatback frame in accordance with the present invention;

FIG. 3 is a cross-sectional view of a variable pivot mechanism for theheadrest of FIG. 2 taken along lines 3—3;

FIG. 4 is a side view of movement of the headrest upon impact inaccordance with the present invention;

FIG. 5 is a perspective view of another embodiment of the variable pivotmechanism in accordance with the present invention;

FIG. 6 is a cross-sectional view of the embodiment in FIG. 4 taken alonglines 6—6;

FIG. 7 is a flow chart of one method of providing head support with amovable headrest of a vehicle seat to a vehicle occupant during reboundfrom a front impact of the vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIG. 1 illustrates a vehicle seat and headrest arrangement 10 havingseat bottom 11 with fore end 11 a and aft end 11 b, seatback 12 withseatback frame 13 joined to seat bottom 11 adjacent aft end 11 b, andheadrest arrangement 14 pivotally and slidably attached to seatbackframe 13. Headrest arrangement 14 includes moveable headrest 22 which,in this and in most typical embodiments, is cushioned. As will bedescribed in greater detail below, headrest 22 moves variably uponvehicle impact. In the embodiment shown, such variable movement occursin first and second manners wherein the first and second manners relateto first and second forward velocities respectively, those being thevelocities of the headrest 22 forward toward the occupant or the frontof the vehicle, and first and second trajectories respectively, thosebeing the trajectories or paths of headrest 22. Such variable movementcould be along any suitable combination of trajectories and velocities.As long as at least one of the first forward velocity and firsttrajectory is different than one of a second forward velocity and secondtrajectory, movement in first and second manners, variable movement, hasbeen achieved. However, as will be explained in more detail, in theevent of a vehicle impact, it is preferable that the headrest move in afirst manner so as to more quickly lessen the gap between the head of anoccupant and the headrest 22 and move in a second manner so as todecrease the forward velocity and provide support upon contact with theoccupant's head.

As will be also described in greater detail below, headrest 22 isguidedly or cammingly moved from the normal position to the actuatedposition upon impact and irrespective of, or prior to, the occupantbeing in contact with the seatback 12.

FIG. 2 depicts headrest arrangement 14 movable with respect to seatbackframe 13. As shown, seatback frame 13 includes upper cross member 16having ends 17, each of which have a side member 18 integrally attachedthereto and extending downwardly therefrom. Lower cross member 20extends across seatback frame 13 to connect side members 18. Lower crossmember 20 may be attached to side members 18 by any suitable means, suchas by bolts (not shown).

In this embodiment, the upper cross member 16 includes at least oneguide member, in this embodiment bushings 21. Such bushings may beattached to the cross member 16 or formed within the cross member 16.While not shown, the guide members could also be connected to any partof the seatback frame. Furthermore, the guide members, such as thebushings 21 shown, may be fixedly, rotatably, or otherwise movablyconnected to seatback frame 13 by any suitable means. In thisembodiment, bushings 21 are welded to upper cross member 16.

As shown, headrest arrangement 14 includes headrest 22 having cushionframe 23, headrest extension 24 extending downwardly therefrom, andimpact target 26 to which extension 24 extends. The impact target 26 mayhave any suitable configuration or shape and may be made from anysuitable material. In this embodiment, impact target 26 is disposedwithin seatback frame 13 and between side members 18. The headrest 22and impact target 26 are operatively associated as the headrestarrangement 14 moves variably with respect to the seat back frame 13. Asdescribed in greater detail below, headrest arrangement 14 cooperateswith seatback frame 13 to define shifting axes about which headrestarrangement 14 pivots.

As depicted in FIGS. 2 and 3, headrest extension 24 extends downwardlyfrom cushion frame 23 through each guide member, in this embodimentbushings 21, to an impact target 26. Each guide member defines aguideway, in this embodiment guideway 25. As shown, the headrestextension 24 in this embodiment constitutes two posts. However, a singlepost or any other suitable extension may be utilized. Likewise, a singleguide member or any other suitable number of guide members may beutilized. Furthermore, while not shown the headrest extension of theheadrest arrangement could include or constitute an upper portion orpart of the seatback frame such that the upper portion or part couldmove variably.

As shown in this embodiment, one or more movement-allowing connectors28, such as links or hinges shown, may be used to pivotally or otherwisesuitably attach impact target 26 to side members 18. Suchmovement-allowing connectors 28 may be connected at each end to theimpact target 26 and side member 18 respectively, in a pivotal, fixed,or otherwise suitable manner. More specifically, as shown in theembodiment depicted, each of the movement-allowing connectors 28 may bepivotally attached to the seatback frame 13 on pivot axis A generallyperpendicular to the fore and aft direction. The other end of themovement-allowing connector may also be pivotally attached to the impacttarget 26. As shown in FIGS. 2 and 4, the pivot axis A is offsetrelative to the impact target 26 such that a rearward force applied tothe impact target 26 will tend to cause the movement-allowing connector28 to pivot about the pivot axis A and the impact target to move in agenerally rearward and upward direction. Of course, any other suitablemovement-allowing connector 28 between the impact target 26 and the sidemember 18, or between any suitable portion of the headrest arrangement14 and the seatback frame 13, could be used, such as multiple linkagesfor example, such that the impact target pivots about a fixed orvariable (instantaneous) pivot axis.

Rearward loading of impact target 26 will cause headrest 22 to pivottoward the head of the occupant. Preferably, a suitable biasing memberis operatively associated with the seatback frame 13 and headrestarrangement 14 in order to bias headrest arrangement 14 against suchmovement. As shown in this embodiment, such biasing member may consistof springs 29 attached between the lower cross member 20 and each link28. However, such biasing member may be operatively associated with orbetween the seatback frame 13 and headrest arrangement 14 in anysuitable manner. Furthermore, while in this embodiment, spring 29 is ametallic coil, any suitable biasing member, such as an elastic tube, maybe used.

As shown in this embodiment, a damper 27 may be connected to the impacttarget 26 and the seatback frame 13 for retarding rearward movement ofheadrest 22 as will be described in further detail. The damper 27 may beany suitable dampening or biasing material, device, or mechanism whichlengthens, expands, or extends under a relatively light or suitabletensile load while suitably retarding, which may include preventing,movement under a compressive load. If one or more dampers 27 areemployed, they may be disposed at any suitable location , and beconnected between the seatback frame 13 or any other suitable component,and the impact target 26, the headrest extension 24, the headrest 22, orany other suitable component in any suitable manner and at any suitablelocation in order to retard rearward movement of headrest 22. Forexample, and without limitation, dampers 27 may be disposed between thelower cross member 20 and links 28.

As shown in FIG. 3, in one embodiment of the present invention the guidemember, in this embodiment the bushing 21, includes a guideway 25, whichin this embodiment includes a cam configuration 31 having a firstmovement portion and a second movement portion, the operation of whichis described in paragraphs below. While the guideway 25 in thisembodiment has a first movement portion and a second movement portion,the guideway 25 is not limited to such a configuration but may have anysuitable configuration. Furthermore, the guide member could utilize aslot or any other suitable configuration in guiding the follower as willbe explained.

The cam configuration 31 in this embodiment includes a first guidewaywall 32 and a second guideway wall 34. As shown, second guideway wall 34may have first contact portion 36 and second contact portion 38 formedvertically adjacent each other and integrally connected. In thisembodiment the first guideway wall 32 has a relatively flat surfaceconfiguration inclined at an angle relative to the adjacent portion ofthe extension 24. The first contact portion 36 and second contactportion 38 of the second guideway wall 34 both have relatively curved orarcuate surface configurations. Of course, any other suitableconfiguration of the first and second guideway walls 32, 34 may be used.Likewise, any suitable configuration of first and second contactportions 36, 38, may be used

As illustrated in FIG. 3, the follower 39, in this embodiment a cam 40,may be disposed on extension 24. Cam 40 may be disposed on extension 24by any suitable means such as by welding or molding. The follower 39, inthis embodiment cam 40, cooperates with the guideway 25 of the guidemember, in this embodiment the bushing 21 having a cam configuration 31with a first guideway wall 32 and second guideway wall 34. While thefollower in this embodiment is a cam, any other suitable followerconfiguration could be utilized, such as a projection projectinglaterally from the extension 24 and engaging a slot or other suitableconfiguration of the guide member. Furthermore, while in this embodimentthe follower is connected to the extension 24 and the guide member isconnected to the seatback frame 13, the follower could also be connectedto the seatback frame 13 and the guide member could be connected to theextension 24.

The follower, in this embodiment the cam 40, has a first followerportion 41 and a second follower portion 43. The second follower portion43 includes a first surface portion 42 and a second surface portion 44formed vertically adjacent each other and integrally connected. As shownin this embodiment, first and second surface portions 42, 44 may havesimilar arcuate or curved surface configurations. However, any othersuitable configurations of the first and second surface portions 42,44may be used and the configurations of the first and second surfaceportions may be mirror images of each other or different. In theembodiment shown, while extending the first surface portion 42 initiallyat approximately 30 degrees from the extension 24 to cooperate with thefirst contact portion 36 of the second passageway wall 34 has been foundto be satisfactory, any suitable angle may be used.

As shown, and as discussed in further detail below, in this embodimentthe first and second surface portions 42, 44 slidably contact first andsecond contact portions 36, 38, respectively, to provide improved headsupport to the occupant upon vehicle impact. Of course, first surfaceportion 42 may also slidably contact second contact portion 38 andsecond surface portion 44 may also slidably contact first contactportion 36 without departing from the spirit or scope of the presentinvention.

As shown in FIGS. 1-4, in this embodiment the first follower portion 41extends from extension 24 opposite first and second surface portions 42,44, and has a first follower end 47 to slidably contact the firstguideway wall 32. While the first follower end 47 of the first followerportion 41 has been shown in this embodiment to have a relatively flatsurface configuration, inclined relative to the extension 24 so as toslidably cooperate with the first passageway wall, any other suitableconfiguration may be used. During normal use of the vehicle seat andheadrest arrangement 10, the first follower portion 41 serves to preventthe extension 24 from shifting back and forth, and to provide asubstantially snug fit within the guide member, in this embodiment thebushing 21.

However, upon vehicle impact, first and second follower portions 41, 43and first and second guideway walls 32, 34, are configured to cooperatetogether to move headrest 22 in first and second manners, e.g., firstand second forward velocities and first and second trajectories ofheadrest 22. More specifically, upon impact of the vehicle, an occupantof the vehicle provides rearward load on impact target 26. In turn,connectors 28 pivot about axis A and the impact target 26 moves in agenerally rearward and upward direction. As a result, extension 24slides upwardly through the guideway 25 of the guide member, in thisembodiment the bushing 21, and first surface portion 42 slides alongfirst contact portion 36, and first follower portion 41 slides alongfirst guideway wall 32. This movement, movement in the first manner,defines the first forward velocity and first trajectory of headrest 22toward and relative to the occupant's head. This movement also definesthe first movement portion. More specifically, this movement in thefirst manner causes the headrest 22 of the headrest arrangement 14 topivot with respect to the seatback frame 13 along a first trajectoryabout and above a constant or shifting axis. The first trajectory andthe force of the impact define a first forward velocity of the headrest22 toward the head of the seat occupant.

Then, the second surface portion 44 slides along second contact portion38, as follower portion 41 continues to slide along and past firstguideway wall 32. This movement, movement in the second manner, definesthe second velocity and second trajectory of headrest 22 toward andrelative to the occupant's head. This movement also defines the secondmovement portion. More specifically, this movement in the second mannercauses the headrest 22 of the headrest arrangement 10 to pivot withrespect to the seatback frame 13 along a second trajectory about andabove a constant or shifting axis. The second trajectory and the forceof the impact define a second forward velocity of the headrest 22 towardthe head of the seat occupant.

Each of the constant or shifting axes is the pivot axis, also called theinstant center axis, instantaneous pivot axis, or instantaneous axis,about which the headrest 22 pivots at any given time during movementalong a particular trajectory.

In the embodiments shown, the pivot axis, also called the instant centeraxis, instantaneous pivot axis, or instantaneous axis, about which theheadrest portion pivots shifts throughout the trajectories of theheadrest 22 during a rearward loading of the impact target. Shifting theinstantaneous axis downwardly allows the headrest 22 to move in a moreforwardly direction toward the occupant's head upon a rearward force tothe impact target. Preferably, the vehicle seat and headrest arrangementis such that the instantaneous axis shifts within a relatively lowerrange of positions during camming between the first surface portion 42and the first contact portion 36. The resulting trajectory is such thatthe headrest 22 will move in a direction more directed toward theoccupant's head during the course of the first trajectory. Shifting theinstantaneous axis upwardly, within a relatively higher range ofpositions, after the movement in the first manner has been accomplished,allows the headrest 22 to move more upwardly, and support the occupant'shead, during movement in the second manner. In the embodiments shown,the cam is formed such that the instantaneous axis shifts upwardly uponcontact of the second surface portion with the second contact portion38.

In summary, upon vehicle impact, the headrest 22 moves forwardly andupwardly in first and second manners, along first and the secondtrajectories, and at first and second forward velocities. The greaterthe crash acceleration, the greater the velocity of headrest 22 in thefirst and second manners.

Although both trajectories provide for both forward and upward movementof the headrest 22, the first trajectory allows the headrest 22 to movemore forwardly and the second trajectory allows the headrest 22 to movemore upwardly. The first forward velocity is preferably greater than thesecond forward velocity. The first forward velocity allows the headrest22 to quickly move a predetermined distance to lessen the gap betweenthe occupant's head and the headrest 22. The second velocity allows theheadrest 22 to further lessen the gap and to slow down or stop relativeto the seat occupant's head for supporting the occupant's head uponcontact.

In this particular embodiment, headrest 22 moves in a forward and upwarddirection for a predetermined distance toward the occupant's head inorder to lessen the gap therebetween. More specifically, during movementof the headrest 22 in the first and second trajectories, the headrest 22is configured to move forward a predetermined distance. While a distancerange between 2 and 25 centimeters may be suitable, any suitabledistance may be used and will be dependent, at least in part, on theinterior design parameters of the particular vehicle.

In the particular embodiment shown, due to the configuration of thefirst surface portion 42 and the first contact portion 36, the headrest22 moves more forwardly than upwardly to define the first trajectory,providing the first forward velocity. Due to the configuration of thesecond surface portion 44 and the second contact portion 38, theheadrest 22 moves more upwardly than forwardly to define the secondtrajectory, providing the second forward velocity. Thus, in thisembodiment, the first forward velocity is greater then the secondforward velocity in the direction toward the head of the vehicleoccupant. Accordingly, surface portions 44, 46 and contact portions 36,38 are designed to reduce headrest 22 movement directly toward theoccupant's head after movement in the first manner.

In normal vehicle seat and headrest arrangements, during the initialstages of an impact, the occupant's torso is in contact with theseatback while the occupant's head is several inches forward of theheadrest 22. This condition is consistent with the body being reclinedat about 20-25 degrees from vertical with the neck being approximatelyvertical. In contrast, the seat is usually at a reclined angle ofapproximately 20-25 degrees from vertical, with the headrest eitherfollowing the inclination of the seatback or curving slightly forward.In any event, for seating comfort, the head is usually not in contactwith the headrest while driving.

As the occupant loads the seatback in an impact, force builds up behindthe torso and buttocks of the seat occupant as the head, neck, torso,and buttocks move in unison. Typically, there is a greater compressionin the torso and buttocks regions of the seat, with a gradual reductionup to the shoulder level as the body remains upright. The more severethe crash, the greater the compression of the occupant into theseatback. As this action is occurring, the initial load of the occupanttends to deflect the seatback rearwardly. The amount of deflection isrelated to the bending stiffness of the seatback. The seatback maypossibly deflect under the torso load prior to the head and neck of theoccupant contacting the headrest. The current invention reduces this“whiplash” effect by bringing the headrest forward into a headsupporting position.

In a front impact of the vehicle, the occupant initially moves forwardrelative to the vehicle seatback. Upon contact with a front interiorpanel or a deployed airbag from the front panel of the vehicle, theoccupant experiences rebound movement in a rearward direction. As theoccupant loads the seatback in a rebound during the front impact, forcebuilds up behind the torso and buttocks of the occupant. Like a rearimpact, depending upon the compliance of the seatback, the occupantcompresses into the cushion as the head, neck, and torso move in unison.In this situation, like in a rear impact situation, there is a greatercompression in the buttocks region than in the shoulder region of theoccupant. Thus, there is a potential that the seatback deflects underthe torso load prior to the head and neck of the occupant contacting theheadrest, resulting in a gap between the head and the headrest in afront crash situation and the potential for a “whiplash” effect.

With the present invention and in the event of a front impact, thesudden substantial deceleration in forward velocity will cause theheadrest 22 to move forward from the normal position, independent of theoccupant contacting the seatback 12 or impact plate 26. Upon frontimpact of the vehicle, when the occupant is initially thrown forward,the forward inertia of the headrest 22 will cause the follower 39 tofollow the guideway 25 such that the first follower end 47 will slidablyengage the first guideway wall 32 while the first surface portion 42slidably engages the first contact portion 36. This allows headrest 22to move at least in the first manner, at the first forward velocity andalong the first trajectory. Then, similar to a rear impact situationdescribed above, the second surface portion 44 will slidably engage thesecond contact portion 38. This allows the headrest 22 to move in thesecond manner, at the second forward velocity and along the secondtrajectory. As in a rear impact situation, the headrest 22 will thenhave moved in a forward direction for a predetermined distance towardthe occupant's head in order to lessen the gap between the headrest andthe occupant's head. The damper 27 serves to retard, which may includepreventing, movement of the headrest back from the actuated or forwardposition back to the non-actuated or normal position before and aftercontact between the occupant's head and the headrest.

FIGS. 5 and 6 depict another embodiment which operates similar to theembodiment described above. This embodiment includes components similarto components of vehicle seat and headrest arrangement 10 above. Similarcomponents will be referred to by the same reference characters used toidentify like components in the first embodiment. However, in thisembodiment, a different guide member, bushing 121, is disposed onseatback frame 113 and includes a first guideway wall 132 and secondguideway wall 134 having a pair of first and second contact portions136, 138. A follower, in this embodiment a cam 140, is disposed onextension 124 and includes a pair of first and second surface portions142, 144 formed to cooperate with the pair of first and second contactportions 136, 138, respectively. As shown, the first guideway wall 132includes a planar surface upon which a first follower portion 141 slidesduring movement of the headrest arrangement 114. Similar to theembodiment described above, the first and second surface portions 142,144 slidably contact the first and second contact portions 136, 138,respectively, to define first and second forward velocities and firstand second trajectories of the headrest 22 during vehicle impact and toaccordingly provide improved head support to the occupant upon vehicleimpact.

While not shown, as a further alternative example embodiment, theinvention may be constructed such that the impact target 26 is notconnected to the side member 18. In such an embodiment, the impacttarget could be supported in the non-impact position via a guide memberand follower for example.

It is to be noted that the embodiments described above may be made byany conventional means using any conventional materials known in thevehicle seating art.

FIG. 7 depicts one method 310 of supporting the head of a vehicleoccupant in a vehicle seat having a seatback and a headrest arrangementmovable with respect to the seatback. Method 310 includes providing theheadrest adapted to be spaced from the head of the occupant in the seatto define a normal or rest position of the headrest arrangement in block312. In the normal position, an instant center of the headrestarrangement is designed or configured substantially lower relative tothe center of gravity of the headrest arrangement. Thus, upon frontimpact of the vehicle in block 314, the headrest arrangementindependently moves from the normal position toward contact with theoccupant's head in a first manner and a second manner to define anactuated position of the headrest, irrespective of the occupant being incontact with the seatback of the vehicle seat. The configuration of theguideway and the follower allows the headrest to independently moveforward to support the occupant's head upon a front impact in a firstmanner and second manner. As described above, the first manner involvesthe headrest moving along a first trajectory at a first forwardvelocity. The second manner involves the headrest moving along a secondtrajectory at a second forward velocity. In block 316, the methodincludes retarding movement of the headrest arrangement back from theactuated position to the normal position, before and after contact withthe head. The damper retards such movement. This provides improvedsupport to the occupant's head from rebound toward the seatback in thecase of a front impact.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

What is claimed is:
 1. A vehicle seat and headrest arrangement for usewith a seat having a seatback in a vehicle, the vehicle seat andheadrest arrangement comprising: a headrest arrangement having aheadrest, the headrest arrangement having one of a guide member and afollower; the seatback having the other one of a guide member andfollower, the guide member having a guideway and the follower extendinglaterally and engaging the guideway of the guide member such that uponimpact to the vehicle forward inertia of the headrest will cause thefollower to engage the guideway in such a manner as to cause theheadrest to move in a manner so as to support a head of an occupantirrespective of whether occupant is in contact with the seatback.
 2. Thevehicle seat and headrest arrangement of claim 1 wherein engagement ofthe follower and the guideway of the guide member together with theforward inertia of the headrest cause the headrest to move in a firstmanner and a second manner so as to support the head of an occupant. 3.The vehicle seat and headrest arrangement of claim 2 further including adamper connected between the headrest arrangement and the seatback so asto retard movement of the headrest after it has moved in a manner so asto support the head of an occupant.
 4. The vehicle seat and headrestarrangement of claim 2 wherein the guide member is a bushing having acam configuration and the follower is a cam such that engagement of thecam and cam configuration together with the forward inertia of theheadrest cause the headrest to move in a first manner and a secondmanner.
 5. The vehicle seat and headrest arrangement of claim 2 whereinthe guideway of the guide member has a first guideway wall and a secondguideway wall and the follower has a first follower portion and a secondfollower portion which engage the first guideway wall and secondguideway wall respectively to cause the headrest to move in a firstmanner and a second manner so as to support the head of an occupant. 6.The vehicle seat and headrest arrangement of claim 5 wherein the secondguideway wall has a first contact portion and a second contact portionand the second follower portion has a first surface portion and a secondsurface portion such that upon impact to the vehicle, the first surfaceportion slidingly engages the first contact portion while the firstfollower portion slidingly engages the first guideway wall so as tocause the headrest to move in a first manner before the second surfaceportion slidingly engages the second contact portion as the firstfollower portion continues to slidingly engage the first guideway wallso as to cause the headrest to move in a second manner.
 7. The vehicleseat and headrest arrangement of claim 6 wherein the first and secondcontact portions and the first and second surface portions haverelatively curved surface configurations and the first guideway wall andfirst follower portion have relatively flat configurations substantiallyparallel to each other and inclined so as to facilitate sliding betweenthe first guideway wall and first follower portion and movement in thefirst manner.
 8. The vehicle seat and headrest arrangement of claim 2further including a movement-allowing connector connected between theheadrest arrangement and the seatback.
 9. The vehicle seat and headrestarrangement of claim 2 further including a biasing member operativelyassociated with the seatback and the headrest arrangement which tends tobias the headrest against movement in a manner so as to support the headof an occupant.
 10. A vehicle seat and headrest arrangement for use witha seat having a seatback in a vehicle, the vehicle seat and headrestarrangement comprising: a headrest arrangement including a headrest, theheadrest arrangement having at least one impact target and at least oneof a guide member and a follower; the seatback having the other at leastone of a guide member and follower, the guide member having a guidewayand the follower extending laterally and engaging the guideway of theguide member such that upon impact to the vehicle one of a rearward loadby the occupant upon the impact target and the forward inertia of theheadrest irrespective of whether occupant is in contact with theseatback will cause the follower to engage the guideway in such a manneras to cause the headrest to move in a manner so as to support a head ofan occupant.
 11. The vehicle seat and headrest arrangement of claim 10wherein the follower engages the guideway such that upon impact to thevehicle the headrest may be moved in a first manner and a second mannerso as to support the head of an occupant by one of a rearward load bythe occupant upon the impact target and the forward inertia of theheadrest irrespective of whether the occupant is in contact with theseatback.
 12. The vehicle seat and headrest arrangement of claim 10further including a damper connected between the headrest arrangementand the seatback so as to retard movement of the headrest after it hasmoved so as to support the head of an occupant.
 13. The vehicle seat andheadrest arrangement of claim 10 wherein the guide member is a bushinghaving a cam configuration and the follower is a cam such thatengagement of the cam and cam configuration together with the forwardinertia of the headrest cause the headrest to move in a first manner anda second manner.
 14. The vehicle seat and headrest arrangement of claim10 wherein the guideway has a first guideway wall and a second guidewaywall and the follower has a first follower portion and a second followerportion which engage the first guideway wall and second guideway wallrespectively to cause the headrest to move in a first manner and asecond manner so as to support the head of an occupant.
 15. The vehicleseat and headrest arrangement of claim 14 wherein the second guidewaywall has a first contact portion and a second contact portion and thesecond follower portion has a first surface portion and a second surfaceportion such that upon impact to the vehicle, the first surface portionslidingly engages the first contact portion while the first followerportion slidingly engages the first guideway wall so as to cause theheadrest to move in a first manner before the second surface portionslidingly engages the second contact portion as the first followerportion continues to slidingly engage the first guideway wall so as tocause the headrest to move in a second manner.
 16. The vehicle seat andheadrest arrangement of claim 15 wherein the first and second contactportions and the first and second surface portions have relativelycurved surface configurations and the first guideway wall and firstfollower portion have relatively flat configurations substantiallyparallel to each other and inclined so as to facilitate sliding betweenthe first guideway wall and first follower portion and movement in thefirst manner.
 17. The vehicle seat and headrest arrangement of claim 11further including a movement-allowing connector connected between theheadrest arrangement and the seatback.
 18. The vehicle seat and headrestarrangement of claim 11 further including a biasing member operativelyassociated with the seatback and the headrest arrangement which tends tobias the headrest against movement in a manner so as to support the headof an occupant.
 19. A vehicle seat and headrest arrangement for use witha seat having a seatback in a vehicle, the vehicle seat and headrestarrangement comprising: a headrest arrangement including a headrest anda headrest extension, the headrest extension having one of a guidemember and a follower and an impact target located below the one of aguide member and a follower; a seatback frame of the seatback having theother one of a guide member and follower, the guide member having aguideway and the follower extending laterally and slidingly engaging theguideway of the guide member such that upon impact to the vehicle one ofa rearward load by the occupant upon the impact target and the forwardinertia of the headrest irrespective of whether occupant is in contactwith the seatback will cause the follower to be slidably guided by theguideway such that the headrest is moved in a first and second manner.20. The vehicle seat and headrest arrangement of claim 17 furtherincluding a movement-allowing connector disposed between the headrestarrangement and the seatback and a biasing member operatively associatedwith the seatback and the headrest arrangement which tends to bias theheadrest against movement in a manner so as to support a head of anoccupant.
 21. The vehicle seat and headrest arrangement of claim 20further including a damper connected between the headrest arrangementand the seatback so as to retard movement of the headrest after it hasmoved so as to support the head of an occupant.
 22. The vehicle seat andheadrest arrangement of claim 21 wherein the guide member is fixedlyattached to the seatback frame and has a first guideway wall and asecond guideway wall and the follower is fixedly attached to theheadrest extension and has a first follower portion and a secondfollower portion which slidingly engage the first guideway wall andsecond guideway wall respectively.
 23. The vehicle seat and headrestarrangement of claim 22 wherein the second guideway wall has first andsecond contact portions having relatively curved surface configurations,the second follower portion has first and second surface portions havingrelatively curved surface configurations, and the first guideway walland first follower portion have relatively flat configurationssubstantially parallel to each other and inclined relative to theheadrest extension such that upon impact to the vehicle, the firstsurface portion slidingly engages the first contact portion while thefirst follower portion slidingly engages the first guideway wall so asto cause the headrest to move in a first manner before the secondsurface portion slidingly engages the second contact portion as thefirst follower portion continues to slidingly engage the first guidewaywall so as to cause the headrest to move in a second manner.
 24. Thevehicle seat and headrest arrangement of claim 1 wherein the headrestarrangement includes the follower disposed on and extending laterallyand outwardly from a headrest extension, and the seatback includes theguide member.